title: Synthesis, characterization, electrochemical and biological studies on some metal(II) Schiff base complexes containing quinoxaline moiety.
abstract: Novel Co(II), Ni(II), Cu(II) and Zn(II) complexes of Schiff base derived from quinoxaline-2,3-(1,4H)-dione and 4-aminoantipyrine (QDAAP) were synthesized. The ligand and its complexes were characterized by elemental analyses, molar conductance, magnetic susceptibility measurements, FTIR, UV-Vis., mass and (1)H NMR spectral studies. The X band ESR spectrum of the Cu(II) complex at 300 and 77K were also recorded. Thermal studies of the ligand and its complexes show the presence of coordinated water in the Ni(II) and Zn(II) complexes. The coordination behavior of QDAAP is also discussed. All the complexes are mono nuclear and tetrahedral geometry was found for Co(II) complex. For the Ni(II) and Zn(II) complexes, octahedral geometry was assigned and for the Cu(II) complex, square planar geometry has been suggested. The grain size of the complexes was estimated using powder XRD. The surface morphology of the compounds was studied using SEM analysis. Electrochemical behavior of the synthesized complexes in DMF at room temperature was investigated by cyclic voltammetry. The in vitro biological screening of QDAAP and its metal complexes were tested against bacterial species Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The fungal species include Aspergillus niger, Aspergillus flavus and Candida albicans. The DNA cleavage activity of QDAAP and its complexes were also discussed.
authors.affiliation: Department of Chemistry, University College of Engineering Nagercoil, Anna University, Tirunelveli Region, Konam, Nagercoil 629 004, Tamil Nadu, India. Electronic address: c.justindhanaraj@gmail.com.
authors.forename: Chellaian Justin
authors.initials: CJ
authors.lastname: Dhanaraj
authors.forename: Jijo
authors.initials: J
authors.lastname: Johnson
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D001424:Bacterial Infections / Q000188:drug therapy; D002417:Cattle; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D004247:DNA / Q000737:chemistry; D053837:DNA Cleavage / Q000187:drug effects; D005658:Fungi / Q000187:drug effects; D006801:Humans; D009181:Mycoses / Q000188:drug therapy; D011810:Quinoxalines / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D012545:Schiff Bases / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D056831:Coordination Complexes; D011810:Quinoxalines; D012545:Schiff Bases; D004247:DNA; C427203:calf thymus DNA
keywords: Antibacterial and antifungal activity; Complexes; DNA cleavage; Quinoxaline; Schiff base